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961.
Pierre Lalonde 《Journal of Combinatorial Theory, Series A》2006,113(6):980-994
We define a bijection that transforms an alternating sign matrix A with one −1 into a pair (N,E) where N is a (so called) neutral alternating sign matrix (with one −1) and E is an integer. The bijection preserves the classical parameters of Mills, Robbins and Rumsey as well as three new parameters (including E). It translates vertical reflection of A into vertical reflection of N. A hidden symmetry allows the interchange of E with one of the remaining two new parameters. A second bijection transforms (N,E) into a configuration of lattice paths called “mixed configuration.” 相似文献
962.
关于随机算子不动点指数的几个定理 总被引:2,自引:1,他引:1
研究了随机半闭1-集压缩算子和随机凝聚算子的随机不动点指数问题,推广了郭大钧文中的几个定理. 相似文献
963.
某液晶显示器温控电路板可靠性强化试验技术研究 总被引:2,自引:0,他引:2
研究了某液晶显示器浊控电路板可靠性强化试验技术,对相关的试验过程和试验结果进行了详细的描述与分析,说明了可靠性强化试验技术在激发产品潜在缺陷、提高产品固有可靠性方面的可行性和有效性。 相似文献
964.
Models for Stationary Max-Stable Random Fields 总被引:3,自引:0,他引:3
Martin Schlather 《Extremes》2002,5(1):33-44
Models for stationary max-stable random fields are revisited and illustrated by two-dimensional simulations. We introduce a new class of models, which are based on stationary Gaussian random fields, and whose realizations are not necessarily semi-continuous functions. The bivariate marginal distributions of these random fields can be calculated, and they form a new class of bivariate extreme value distributions. 相似文献
965.
Yiorgos-Sokratis Smyrlis 《BIT Numerical Mathematics》2006,46(1):163-194
We investigate the Method of Fundamental Solutions (MFS) for the solution of certain elliptic boundary value problems. In
particular, we study the case in which the number of collocation points exceeds the number of singularities, which leads to
an over-determined linear system. In such a case, the resulting linear system is over-determined and the proposed algorithm
chooses the approximate solution for which the error, when restricted to the boundary, minimizes a suitably defined discrete
Sobolev norm. This is equivalent to a weighted least-squares treatment of the resulting over-determined system. We prove convergence
of the method in the case of the Laplace’s equation with Dirichlet boundary data in the disk. We develop an alternative way
of implementing the numerical algorithm, which avoids the inherent ill-conditioning of the MFS matrices. Finally, we present
numerical experiments suggesting that introduction of Sobolev weights improves the approximation.
AMS subject classification (2000) 35E05, 35J25, 65N12, 65N15, 65N35, 65T50 相似文献
966.
Tomá s Caraballo Hans Crauel José A. Langa James C. Robinson 《Proceedings of the American Mathematical Society》2007,135(2):373-382
We investigate the effect of perturbing the Chafee-Infante scalar reaction diffusion equation, , by noise. While a single multiplicative Itô noise of sufficient intensity will stabilise the origin, its Stratonovich counterpart leaves the dimension of the attractor essentially unchanged. We then show that a collection of multiplicative Stratonovich terms can make the origin exponentially stable, while an additive noise of sufficient richness reduces the random attractor to a single point.
967.
Twist stiffness and an asymmetric bending stiffness of a polymer or a polymer bundle is captured by the elastic ribbon model.
We investigate the effects a ring geometry induces to a thermally fluctuating ribbon, finding bend-bend coupling in addition
to twist-bend coupling. Furthermore, due to the geometric constraint the polymer's effective bending stiffness increases.
A new parameter for experimental investigations of polymer bundles is proposed: the mean square diameter of a ribbonlike ring,
which is determined analytically in the semiflexible limit. Monte Carlo simulations are performed which affirm the model's
prediction up to high flexibility. 相似文献
968.
S. M.D. Queirós L. G. Moyano J. de Souza C. Tsallis 《The European Physical Journal B - Condensed Matter and Complex Systems》2007,55(2):161-167
We present results about financial market observables, specifically
returns and traded volumes. They are obtained within the current nonextensive statistical mechanical framework based on the
entropy
. More precisely, we present stochastic dynamical mechanisms which mimic probability density functions empirically observed.
These mechanisms provide possible interpretations for the emergence of the entropic
indices q in the time evolution of the corresponding observables. In addition to this, through multi-fractal analysis of return
time series, we verify that the dual relation qstat+qsens=2 is numerically satisfied, qstat and qsens being associated to the probability density function and to the sensitivity to initial conditions respectively. This type
of simple relation, whose understanding remains ellusive, has been empirically verified in various other systems. 相似文献
969.
In this paper, we propose a Quasi-Orthogonal Matching Pursuit (QOMP) algorithm for constructing a sparse approximation of functions in terms of expansion by orthonormal polynomials. For the two kinds of sampled data, data with noises and without noises, we apply the mutual coherence of measurement matrix to establish the convergence of the QOMP algorithm which can reconstruct $s$-sparse Legendre polynomials, Chebyshev polynomials and trigonometric polynomials in $s$ step iterations. The results are also extended to general bounded orthogonal system including tensor product of these three univariate orthogonal polynomials. Finally, numerical experiments will be presented to verify the effectiveness of the QOMP method. 相似文献
970.
Omar Alkhazragi Hang Lu Wenbo Yan Nawal Almaymoni Tae-Yong Park Yue Wang Tien Khee Ng Boon S. Ooi 《Annalen der Physik》2023,535(9):2300289
Random number generation (RNG) is needed for a myriad of applications ranging from secure communication encryption to numerical simulations to sports and games. However, generating truly random numbers can be elusive. Pseudorandom bit generation using computer algorithms provides a high random bit generation rate. Nevertheless, the reliance on predefined algorithms makes it deterministic and predictable once initial conditions are known. Relying on physical phenomena (such as measuring electrical noise or even rolling dice) can achieve a less predictable sequence of bits. Furthermore, if the physical phenomena originate from quantum effects, they can be truly random and completely unpredictable due to quantum indeterminacy. Traditionally, physical RNG is significantly slower than pseudorandom techniques. To meet the demand for high-speed RNG with perfect unpredictability, semiconductor light sources are adopted as parts of the sources of randomness, i.e., entropy sources, in quantum RNG (QRNG) systems. The high speed of their noise, the high efficiency, and the small scale of these devices make them ideal for chip-scale QRNG. Here, the applications and recent advances of QRNG are reviewed using semiconductor emitters. Finally, the performance of these emitters is compared and discuss their potential in future technologies. 相似文献